Computer auxiliary gear box

ABSTRACT

A converter attachable to a variator of a fuel pump computer for expanding its price range wherein the converter has an auxiliary gear box group including a variator drive gear and step-up gearing having a drive gear supported for rotation on an axially shiftable converter shaft drivingly connected to a meter driven rotary input, and a converter operating mode drive coupling mounted on the converter shaft for selectively coupling the converter shaft to the variator drive gear and the step-up gearing as determined by the axial position of the converter shaft.

United States Paten 1 1 3,916,166

Smilgys Get. 28, 1975 COMPUTER AUXILEARY GEAR BOX Primary Examiner-Stephen J. Tomsky [75] Inventor: Bruno S. Smilgys, Hartford Conn. g Agent or Firm pmtzman Hayes Kalb &

ilton [73] Assignee: Veeder Industries, Inc., Hartford,

Conn- 57 ABSTRACT [22] Filed: Sept. 6, 1974 A converter attachable to a variator of a fuel pump computer for expanding its price range wherein the [21] Appl' 503515 converter has an auxiliary gear box group including a variator drive gear and step-up gearing having a drive [52] US. Cl. 235/94 R; 235/61 L; 235/61 M gear supported for rotation on an axially shiftable con- [51] Int. Cl. G06C 15/42; B07D 5/22 rter shaf rivingly connected to a meter driven ro- [58] Field of Search 235/94 R, 94 A, 61 L, 61 M tary input, and a converter operating mode drive coupling mounted on the converter shaft for selectively [56] Referen es Cited coupling the converter shaft to the variator drive gear UNITED STATES PATENTS and the step-up gearing as determined by the axial po- 3,863,839 2/1975 Batson 235/94 R of the converter Shaft 10 Claims, 3 Drawing Figures PluR QUART US. Patent Oct. 28, 1975 Sheet 1 of?! 3,916,166

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COMPUTER AUXILIARY GEAR BOX SUMMARY OF THE INVENTION This invention relates to mechanical fuel pump computers of a type employed in gasoline dispensing apparatus for establishing and posting a unit volume price for a gallon of fuel, registering the volume of fuel delivered in gallons and computing and registering the cost of fuel delivered in dollars and cents. A conventional mechanical register of a type used in such computers is shown and described in US. Pat. No. 2,814,444 of Harvey N. Bliss dated Nov. 26, 1957, entitled Register and assigned to the assignee of this invention. Such computers also employ mechanical variators of a type shown and described in US. Pat. No. 3,413,867 of Richard B. Hamlin dated Dec. 3, 1968, entitled Variator and assigned to the assignee of this invention. More specifically, this invention particularly concerns a converter for such mechanical fuel pump computers cordance with volume of fuel delivered and the posted unit volume price.

A conventional mechanical fuel pump computer incorporates a mechanical register having a pair of counters on each of two opposite faces of the register for registering, on each of the opposite faces, the cost of fuel delivered in dollars and cents and the volume of fuel delivered in gallons. Such a register is shown in referenced US. Pat. No. 2,814,444. The fuel pump computer also incorporates a mechanical variator of the type disclosed in referenced US. Pat. No. 3,413,867 for establishing and posting the unit volume price for a gallon of fuel. The variator is connected to be mechanically driven by a conventional gasoline meter so that the variator center shaft is rotated four revolutions for each gallon of fuel delivered. The variator is also connected for driving the volume and cost counters of the register for registering the volume amount of fuel delivered in gallons and the cost amount of fuel delivered in dollars and cents in accordance with the volume amount of fuel delivered in gallons and the gallon unit volume price established by the variator setting.

Because of the increasing cost of gasoline, the price of'a gallon of gasoline now frequently exceeds the maximum range of 49 and 9/10 cents of conventional limited range variators in the field. In the future, the price of gasoline may exceed the maximum range of 99 and 9/10 cents of conventional greater range variator-s in the field.

Also, consideration is being given to converting to the metric measuring system in which event the present gallons measure used in fuel pump computers may, by requirement or by choice, be changed to 21- liters measure. Because of the foregoing considerations, it may become desirable, essential or even mandatory to convert existing mechanical fuel pump computers from the present gallon unit volume price setting and gallon volume registration of fuel delivered to provide a quart or liter unit volume price setting and a volume registration in quarts or liters of fuel delivered.

' Therefore, a principal advantage of this invention is in the provision of a fuel pump computer converter for selectively converting conventional mechanical fuel pump computers for establishing and posting a unit volume price in quarts or liters, for registering the volume amount of the fuel delivered in quarts/liters and registering the cost amount of the fuel delivered in dollars and cents in accordance with the volume amount delivered in quarts/liters and a quart/liter unit volume price established by the setting of the variator.

Another advantage of this invention is the provision of a new and improved converter of the type described which permits field conversion of existing conventional computers with minimum inconvenience and down time.

A further advantage of this invention is the provision of a new and improved selectively operable converter for a mechanical gasoline pump computer settable alternatively for establishing either a gallon unit volume price and registering the fuel delivered in gallon amounts in the conventional manner, or a unit volume price in either quarts/liters and for registering the volume amount of fuel delivered in quarts/liters.

Still another advantage of this invention is the provision of a new and improved selectively operable converter for a gasoline pump computer which may be selectively set quickly and easily from a gallon setting to a quart/liter setting, or from a quart setting to a liter setting when desired, and which features an axially shiftable converter shaft for effecting facile changeover which is positively maintained in position once changeover to a different computation is made.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

A better understanding of this invention will be obtained from the following detailed description and the accompanying drawings of an illustrative application of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial front elevational view, partly broken away, of a fuel pump having a mechanical computer modified in accordance with this invention;

FIG. 2 is an enlarged elevational view, partly broken away and partly in section, of an auxiliary gear box of a modified mechanical computer; and

FIG. 3 is an enlarged elevational view, partly broken away and partly in section, of another type auxiliary gear box according to this invention for a modified mechanical computer.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to the drawings in detail, a gasoline delivery pump 10 employing a mechanical computer 12 modified in accordance with this invention is shown having a nozzle 14 for delivering fuel and a suitable nozzle storage receptacle 15 for storing the nonle 14 between deliveries. A meter 16 is conventionally provided in the fuel delivery conduit and has a rotary output shaft 17 which rotates at a speed proportional to the volume amount of fuel delivered. The meter shaft 17 is suitably connected to a lower female coupling 18 of a rotary input shaft 19 of a modified variator 20 for rotating the variator input shaft 19 at a rate of four revolutions per gallon of fuel dispensed.

Exceptas modified as hereinafterdescribed, the variator may be of the type described .in the aforementioned U.S. Pat. No. 3,413,867. and comprises three settable range arms (not shown) of ascending order of significance which can be individually manually set into engagement with selected gear steps of a cone gear (not shown) to collectively establish the desired unit volume price of fuel within a threeplace price range as fully shown and describedin U.S. Pat. No. 3,413,867, the subject matter of which is incorporated herein by reference. The variator 20 also comprises three price posting wheels 21, 22 and 23, corresponding to the three range arms, which are mechanically "connected to the range arms to automatically post the unit volume price established by the settings of the range arms.

The variator 20 has a center shaft 30 driven by the variator input shaft 19 (as hereinafter described) and which extends through the variator 20 and has a suitable mechanical driving connection as at 32 for driving the lowest order counter wheels (such as the one shown at 24) of a pair of register volume counters such as at 25 for registering the volume amount of fuel dispensed.

A rotary output gear 26 of the variator is rotatably mounted on the variator center shaft 30 and is driven by the meter 16 via the variator cone gear and variator range arms in accordance with the established unit volume price. The output gear 26 is mechanically connected somewhat like the variator shaft 30 for driving the lowest order counter wheels (such as at the one shown at 37) of a pair of register cost counters such as at 38 for registering the cost amount of fuel dispensed in accordance with the unit volume price established by the variator 20.

The resettable register volume and cost counters 25 and 38 are of a type fully shown and described in the aforementioned U.S. Pat. No. 2,814,444, the subject matter of which is incorporated herein by reference. The counters of the register are operable by a control handle 39 positioned adjacent the nozzle storage receptacle 15 such that the handle 39 has to be rotated to its vertical or off position to permit the nozzle 14 to be placed in its storage receptacle at the completion of a fuel delivery, The nozzle l4has to be removed from its storage receptacle 15 to permit the handle 39 to be rotated to its horizontal or on position. Rotation of the handle 39 to its vertical or off position provides for disengaging all number wheels for conditioning the register counters to be reset. Rotation of handle 39 to its horizontal or on position provides for sequentially resetting all number wheels of the volume and cost counters 25 and 38 to zero and then re-engaging all wheels for reconditioning the register for registering the cost and volume of the next fuel delivery. The register is also connected in a known manner as described in U.S. Pat. No. 2,814,444 to provide for deenergizing a motor 46 for a pump 48 when the handle 39 is turned to its off position, and for re-energizingmotor 46 after the volume and cost counters 25, 38 of the register have been reset and the register is conditioned for recording the next delivery.

As more fully described inthe aforementioned U.S. Pat. No. 2,814,444, the register includes the previously mentioned pair of cost and volume counters 25 and 38 on each of two opposed sides of the register, only one pair of cost and volume counters being shown in the drawings. The lowest order counter wheel of each cost counter 38 is mechanically connected to be driven by the meter 16 via the variator 20 for registering the cost of each fuel delivery. The lowest order counter wheel of each volume counter 25 is mechanically connected to be driven by the meter 16 via the variator 20 for registering the volume of each fuel delivery.

As described, the conventional mechanical computer is installed to establish and post the unit volume price of a gallon of fuel with the variator 20, to register the volume amount of fuel delivered in gallons and to computethe cost amount of fuel delivered in accordance with the number of gallons delivered and the gallon unit volume price established by the variator setting. A conventional fuel pump computer may be modified from a gallons measure to register the volume amount of fuel delivered in quarts and to compute the fuel cost in accordance with the number of quarts delivered. Such a change may be effected without changing the drive connections between the counters 25, 38 and the meter 16, other than the gear ratios. The variator 20 may be set in a known manner at one-fourth the price of a gallon of fuel to provide a quart unit volume price, and the volume and cost counters 25 and 38 of the pump register may be modified and their drive ratios may be increased and reduced respectively by a factor of four to register the total volume and cost of fuel delivered based on the posted quart unit volume price. Such a modification may be effected by replacing the lowest order volume and cost counter wheels with substitute wheels having forty gr'aduations instead of the conventional ten, and a modified combination locking ring and transfer gear is provided in the counters 25 and 38 for indexing the next higher order counter wheel in response to rotation of the lowest order wheel of each counter 25, 38, Such modification of a conventional computer is fully shown and described in the above mentioned U.S. patent application Ser. No. 442,476, the subject matter of which is incorporated herein by reference.

Once a computer has been converted as described above, it can then be readily converted from a quart unit volume system to a liter unit volume system.

A converter unit for readily effecting such conversion is provided in accordance with this invention and one embodiment of such a unit is illustrated in FIG. 2. More specifically, the variator 20 is modified to incorporate a selectively settable auxiliary input gear box or converter 40 on an underside of a conventional base 42 of variator 20. Input gear box 40 could be installed with the provision of suitable fasteners on the underside of the base 42 when variator 20 is originally installed in the pump 10. If desired, gear box 40 also can be later installed on an existing variator during field conversion of the computer 12 to establish and post a unit volume price of a quart/liter of gasoline. For the purpose of permitting advance installation of the gear box 40, it is also designed to selectively provide a 1:1 drive ratio for gallons pricing and cost computation in a conventional manner as described.

Gear box 40 includes variator drive gear 44 having an upwardly projecting hub mounted on a depending end of variator drive center shaft 30. A transversely extending opening is fonnedthrough the variator center shaft 30, and a coupling pin 46 is press fit through the opening in shaft 30 and is received within diametrically 0pposed openings in the hub of variator drive gear 44 which register with the opening in shaft 30 to key the variator drive gear 44 to variator center shaft 30.

Variator drive gear 4 1 includes a pair of radial openings 48, 48 extending in opposed radial directions as shown in FIG. 2 for receiving opposite ends of a pin 50 extending diametrically through an axially shiftable converter shaft 52 telescopically received within a collar of a rotary input shaft 19 supported on a thrust washer 54 on gear box housing 56. Pin 50 will be seen to be axially shiftable in a downward direction as viewed in FIG. 2 into radial openings 58, 58 formed in the surface of a drive gear 60 confronting gear 44. Drive gear 60 is supported for rotation on converter shaft 52 by thrust washer 62 interposed between the drive gear 60 and the collar of rotary input shaft 19.

The axially shiftable converter shaft 52 may be operatively positioned as illustrated in FIG. 2 with the pin 50 serving as a converter operating mode drive coupling between converter shaft 52 and the variator drive gear 44. In the first illustrated operating position shown in FIG. 2, converter shaft 52 is retained by a cotter pin 64 which extends through diametrically opposed openings in the input shaft 19 which will be understood to be designed with a female coupling at its depending end to provide an input from the meter 16 to the variator 20. In the illustrated operating position, converter shaft 52 is retained in position and compresses a coil compression spring 66 shown coaxially mounted within the hub of variator drive gear 44 between the variator center shaft 30 and the axially shiftable converter shaft 52.

To effect a drive connection between the input shaft 19 and the converter shaft 52 while yet permitting its being axially shifted, a drive pin 68 is press fit in shaft 52 to extend therethrough transversely to its longitudinal axis with opposite ends of the pin 68 extending through conforming axially extending slots such as the one shown at 70 formed in the input shaft 19.

In its illustrated operating position, the converter shaft 52 will be understood to establish a direct 1:1 drive ratio from the input shaft 19 to the variator drive gear 44 whereby conventional gallons pricing and cost computation may be established in a conventional manner as described. If desired, upon selective modification of the fuel pump computer as described above, the gear box 40 may be utilized in the illustrated mode to provide a 1:1 drive ratio for establishing quarts pricing and cost computation.

When it is desired to effect conversion from gallons or quarts pricing and cost computation to liters, e.g., and thereby to significantly expand the price range of computer 12, the cotter pin 64 is removed to permit the converter shaft 52 to be lowered under the bias of the spring 66 to position drive pin 50 within the conforming openings 58, 58 in drive gear 60 which was previously freely rotatable about converter shaft 52 in its illustrated operating position. Once positioned in the lower or second operating position, the converter shaft 52 is coupled by its pin 50 to gear 60 of step-up gearing 72 through its driven compound gear 74 supported on shaft 76 mounted on housing 56 in parallel relation to the variator center shaft 30. The driven compound gear 74 has first and second gears 78 and 80 respectively in meshing engagement with drive gear 60 and variator drive gear 44 to provide a gear ratio which is stepped up relative to the direct 1:1 drive ratio established by the converter shaft 52 in its first operating position.

Depending upon the drive ratio established between the input shaft 19 and the variator drive gear 44 when the axially shiftable converter shaft 52 is moved onto its lower operating position, the converter 40 may be employed to provide a changeover from Imperial gallons, e.g., to liters or from standard United States gallons to liters. To provide a conversion from Imperial gallons to liters, a gear ratio of 1:4.545 speed up is established through gear box 10; likewise, with respect to effecting a conversion from a United States gallons system to liters systems, the gear box drive ratio required is a 1:3.785 increase.

Accordingly, a computer may be modified by virtue of the above described field convertible gear box for selectively converting the computer from either an Imperial or United States gallons computation and registration system to a liters computation and registration system, it being understood that the face of the register must be modified accordingly to provide proper indication of the unit of volume on which the computation and registration is based.

Turning now to that embodiment of the converter constructed in accordance with this invention as shown in FIG. 3, the same numbers are utilized to identify like parts as in the embodiment of FIG. 2. The variator converter or gear box has a variator drive gear 144 supported for rotation upon an axially shiftable converter shaft 152 which is telescopically mounted within the tubular rotary input shaft 19 supported for rotation on a thrust bearing 200 interposed between the collar of shaft 19 and the base of the gear box housing 56. The variator drive gear 144 is coupled by a pin 146 for a direct driving connection to the variator center shaft 30 wherein the pin extends through an opening in the variator center shaft 30 into diametrically opposed axially extending slots such as at 202 in an upwardly axially extending hub of the variator drive gear 144.

In the converter shaft 152, a spring chamber or slot 204 is formed transversely of the longitudinal axis of the shaft 152 and a coil compression spring 206 is fitted within chamber 204 to urge a flat disc shaped detent or pawl 208 received for transverse movement within the slot 204 radially outwardly into a slot 209 formed on an inner diameter wall of the variator drive gear 144. Accordingly, a direct drive ratio of 1:1 is established between the variator drive gear 144 and the converter shaft 152 which in turn is directly coupled to input shaft 19 via a pin 168 extending through aligned axially extending slots such as at 170 in the input shaft 19. Pin 168 is shown in FIG. 3 as being in an upper operating position and is retained thereby by a releasable locking ring 210 fitted within a peripheral groove or annulus formed in the input shaft 19 with the locking ring 210 located below the upper end of slots 170 in interfering relation to opposite ends of the pin 168 to prevent its being lowered unintentionally.

By virtue of the above described construction with the converter shaft 152 in its first or upper operating position as illustrated in FIG. 3, a direct 1:1 drive is effected between the input shaft 19 and the variator drive gear 144 to variator center shaft 30 whereby a gallons computation and registration system may be provided.

To effect conversion to quarts or liters computation and registration systems, the axially shiftable converter shaft 152 is designed to provide different drive ratios from the input shaft 19 to the center shaft 30 by virtue of the provision of step-up gearing 172 having first and second converter drive gears 212 and 214 which are supported for rotation on the axially shiftable converter shaft 152. Gear 212 is in meshing engagement with a first gear 216 of a compound driven gear 174 having a second gear 218 in meshing engagement with the variator drive gear 144. The compound gear 174 is supported for rotation on a shaft 176 mounted in the gear box housing3156 in parallel relation to the variator center shaft" 30. The second or lower converter drive gear 214 is inmesh with a third gear 220 of the compound gear 174.

To shift the converter shaft 152 into a mid-position wherein disc detent 208 is moved out of its illustrated upper operating position or 1:1 drive ratio position into driving engagement with the gear 212, the locking ring 210 is removed from the annulus and the converter shaft 152 is permitted to be lowered to an extent limited by a second locking ring 224 fitted within annulus 226 on shaft 19, the ring 224 being understood to be interfering relation to pin 168 which will be located at 228 to condition the computer for expanded pricing. With pin 168 in mid-position at 228, the spring loaded disc detent 208 is moved into registration with the slot opening 230 in the first converter drive gear 212. The locking ring 210 is preferably replaced in its annulus formed on the input shaft 19 and the converter shaft 152, which is normally retained in position under its own weight, will also be prevented from moving upwardly beyond its second or mid-operating position. In the mid-position, the converter shaft 152 is suited to provide a gear ratio increase of 1:4 from the input shaft 19 to the variator drive gear 144 whereby a desired quarts computation and registration system is effected. This may be effected, for example, by gears 212, 216, 218 and 144 respectively formed with 63, 21, 36 and 27 teeth.

To effect a liters computation and registration system, a 1:3.785 increased drive ratio must be established from the input shaft 19 to the variator drive gear 144. This is effected by the lowermost operating position of the axially shiftable converter shaft 152 whereby the disc detent 208 is moved into a drive position within slot opening 232 of the second converter drive gear 214 supported on the converter shaft 152. Such a drive connection may be established by temporarily removing locking ring 224 to permit pin 168 to drop into its lowermost position as shown at 234 whereupon the locking ring is again positioned in annulus 226 to prevent any unintended substantial upward movement of the converter shaft 152. Thereupon, a drive connection is established between the input shaft 19 and the variator drive gear 144 via the converter shaft 152, the lowermost converter drive gear 214, and the gears 220 and 218 of the compound gear 174. To provide the desired 1:3.785 step-up in the gearing, gears 214, 220, 218 and 144 may be provided respectively with 53, 21, 36 and 24 teeth.

It will be seen that a single alternative drive ratio stepup may be provided beyond the direct 1:1 drive ratio, e.g., wherein a two position converter shaft may be provided with only one converter drive gear and two driven gears of a compound gear with a coupling pin either above or below a single locking ring to effect a liters conversion, say, from a direct 1:1 drive ratio between the input shaft and the variator drive gear which would be suitable for effecting a gallons computation and registration or a quarts computation and registration if the variator and register were modified as described above. Once such a system were changed from direct drive to shift the converter shaft and disc detent into a lower position below the single locking ring of such a gear box, the lower position could establish, e.g., a liters pricing system. It is also to be understood that should the stepped-up gear ratio achieved by the gearing not be precisely what is required, suitable correction may be effected by meter adjustment within the adjustment range of the meter 16.

From the foregoing description, it will be apparent that various embodiments of converters of this invention will provide facile conversion of existing conventional fuel pump computers and will also provide such conversion not only for prior installation of the converter unit in a new fuel pump converter, but will also be equally adaptable to field conversion of existing computers. Once the decision has been made to make such a conversion, the implementation is quick and easy and the gear box group is relatively economical to manufacture and assemble with minimum field service being required.

As will be apparent to persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teachings of the present invention.

1 claim:

1. For use with a mechanical fuel pump computer having a variator and a register wherein the variator has an input shaft normally driven by a fuel meter in accordance with the volume of fuel delivered and is settable to establish a selected unit volume fuel price normally within a three place price range and wherein the register has a resettable volume counter drivingly connected to the meter via the variator to normally reflect total gallons of each fuel delivery and a resettable cost counter connected to be driven by the meter via the variator in accordance with its setting to provide a price readout of the total cost of each fuel delivery, a converter for expanding the price range of the computer and for setting the computer to compute and register total volume and cost of each fuel delivery based on a unit volume price for gallons and alternatively for another unit of reduced volume such as quarts or liters, the converter comprising a rotary output including a variator drive gear, a rotary input coaxially aligned with the variator drive gear, a converter shaft connected to be driven by the rotary input and disposed in coaxial relation to the rotary input and variator drive gear, step-up gearing for establishing an increased drive ratio from the rotary input to the rotary output, and a com verter operating mode drive coupling mounted on the converter shaft for selective engagement with the variator drive gear and the step-up gearing, the converter shaft being axially shiftable into first and second operating positions to selectively establish first and second converter settings for operating the computer, the converter shaft in said first operating position being coupled by the drive coupling directly to the variator drive gear in 1:1 drive ratio from the rotary input to the rotary output for gallons volume registration and cost computation, the converter shaft in said second operating position being coupled by the drive coupling to the step-up gearing in an increased drive ratio from the rotary input to the rotary output for volume registration and cost computation for units of reduced volume such as quarts or liters.

2. The converter of claim 1 further including an auxiliary gear box housing, the housing being attachable to an underside of the variator with the rotary input supported for rotation on the housing in coaxial alignment with the variator drive gear and the converter shaft.

3. The converter of claim 1 wherein one of the rotary input and the converter shaft members is of a tubular construction and the other member is telescopically received within said one member, and wherein a pin and slot rotary driving connection is established between the rotary input and the converter shaft while permitting axial shifting of the converter shaft between its first and second operating positions.

4. The converter of claim 1 further including releasable locking means for releasably locking the converter shaft in its first operating position.

5. The converter of claim 1 wherein said operating mode drive coupling comprises a diametrically extending drive coupling pin having an end projecting from the converter shaft, the step-up gearing having a first gear mounted on the converter shaft and a compound driven gear in meshing engagement with said first gear and the variator drive gear, the variator drive gear and said first gear having confronting surfaces with a slot in each of the surfaces for alternatively receiving the projecting end of the drive coupling pin of the converter shaft to selectively couple it to the variator drive gear and the step-up gearing.

6. The converter of claim 5 further including a spring between the rotary output and the converter shaft, re-

leasable locking means for releasably maintaining the converter shaft in its first operating position with the drive coupling pin in driving engagement with the variator drive gear, the spring effecting axial shifting of the converter shaft upon release of the locking means to disengage the drive coupling pin from the variator drive gear and to shift the converter shaft into driving engagement with said first gear of the step-up gearing.

7. The converter of claim 1 wherein the step-up gearing has a first converter drive gear mounted on the converter shaft and a compound driven gear with first and second compound gears in meshing engagement with said first converter drive gear and the variator drive gear, wherein the variator drive gear and said first converter drive gear each have a detent receiving aperture formed on an inside diameter of the respective gears, wherein the converter shaft has a radial chamber formed in the shaft for communication with said apertures, wherein the operating mode drive coupling com prises a detent mounted in the chamber for movement radially of the converter shaft and biased radially outwardly for receipt alternatively within the detent apertures of the variator drive gear and said first converter drive gear for selectively coupling the converter shaft to the variator drive gear and the step-up gearing.

8. The converter of claim 7 wherein a pin and slot rotary driving connection is established between the rotary input and the converter shaft while permitting axial shifting of the converter shaft between its operating positions, and wherein releasable locking means is provided on the rotary input engageable with the pin of the pin and slot driving connection for maintaining the converter shaft in a selected first and second operating position.

9. The converter of claim 7 wherein the step-up gearing includes a second converter drive gear mounted on the converter shaft and a third compound gear in meshing engagement therewith, said first converter drive gear upon being coupled to the converter shaft by the detent establishing said second operating position with a stepped-up drive ratio of 1:4 from the rotary input to the rotary output via the step-up gearing for volume registration and cost computation for quarts of fuel dispensed, said second converter drive gear having a detent receiving aperture which upon axial shifting of the converter shaft with its detent received in the aperture of said second converter drive gear establishes a third operating position with a 1:3.785 drive ratio from the rotary input to the rotary output via the step-up gearing for volume registration and cost computation for liters of fuel dispensed.

10. The converter of claim 9 wherein the rotary input has a tubular end for telescopically receiving the counter shaft, the rotary input having an axially extending slot, wherein the converter shaft has a diametrically extending pin with an end of the pin received in the slot of the rotary input and providing a pin and slot rotary driving connection between the rotary input and the converter shaft, wherein first and second annuli are formed in the rotary input between the ends of its slot therein, and wherein a pair of locking rings are releasably secured in the annuli of the rotary input and which locking rings are engageable with the end of the pin for selectively retaining the converter shaft in first, second and third operating positions. 

1. For use with a mechanical fuel pump computer having a variator and a register wherein the variator has an input shaft normally driven by a fuel meter in accordance with the volume of fuel delivered and is settable to establish a selected unit volume fuel price normally within a three place price range and wherein the register has a resettable volume counter drivingly connected to the meter via the variator to normally reflect total gallons of each fuel delivery and a resettable cost counter connected to be driven by the meter via the variator in accordance with its setting to provide a price readout of the total cost of each fuel delivery, a converter for expanding the price range of the computer and for setting the computer to compute and register total volume and cost of each fuel delivery based on a unit volume price for gallons and alternatively for another unit of reduced volume such as quarts or liters, the converter comprising a rotary output including a variatoR drive gear, a rotary input coaxially aligned with the variator drive gear, a converter shaft connected to be driven by the rotary input and disposed in coaxial relation to the rotary input and variator drive gear, step-up gearing for establishing an increased drive ratio from the rotary input to the rotary output, and a converter operating mode drive coupling mounted on the converter shaft for selective engagement with the variator drive gear and the step-up gearing, the converter shaft being axially shiftable into first and second operating positions to selectively establish first and second converter settings for operating the computer, the converter shaft in said first operating position being coupled by the drive coupling directly to the variator drive gear in 1:1 drive ratio from the rotary input to the rotary output for gallons volume registration and cost computation, the converter shaft in said second operating position being coupled by the drive coupling to the step-up gearing in an increased drive ratio from the rotary input to the rotary output for volume registration and cost computation for units of reduced volume such as quarts or liters.
 2. The converter of claim 1 further including an auxiliary gear box housing, the housing being attachable to an underside of the variator with the rotary input supported for rotation on the housing in coaxial alignment with the variator drive gear and the converter shaft.
 3. The converter of claim 1 wherein one of the rotary input and the converter shaft members is of a tubular construction and the other member is telescopically received within said one member, and wherein a pin and slot rotary driving connection is established between the rotary input and the converter shaft while permitting axial shifting of the converter shaft between its first and second operating positions.
 4. The converter of claim 1 further including releasable locking means for releasably locking the converter shaft in its first operating position.
 5. The converter of claim 1 wherein said operating mode drive coupling comprises a diametrically extending drive coupling pin having an end projecting from the converter shaft, the step-up gearing having a first gear mounted on the converter shaft and a compound driven gear in meshing engagement with said first gear and the variator drive gear, the variator drive gear and said first gear having confronting surfaces with a slot in each of the surfaces for alternatively receiving the projecting end of the drive coupling pin of the converter shaft to selectively couple it to the variator drive gear and the step-up gearing.
 6. The converter of claim 5 further including a spring between the rotary output and the converter shaft, releasable locking means for releasably maintaining the converter shaft in its first operating position with the drive coupling pin in driving engagement with the variator drive gear, the spring effecting axial shifting of the converter shaft upon release of the locking means to disengage the drive coupling pin from the variator drive gear and to shift the converter shaft into driving engagement with said first gear of the step-up gearing.
 7. The converter of claim 1 wherein the step-up gearing has a first converter drive gear mounted on the converter shaft and a compound driven gear with first and second compound gears in meshing engagement with said first converter drive gear and the variator drive gear, wherein the variator drive gear and said first converter drive gear each have a detent receiving aperture formed on an inside diameter of the respective gears, wherein the converter shaft has a radial chamber formed in the shaft for communication with said apertures, wherein the operating mode drive coupling comprises a detent mounted in the chamber for movement radially of the converter shaft and biased radially outwardly for receipt alternatively within the detent apertures of the variator drive gear and said first converter drive gear for selectively couplinG the converter shaft to the variator drive gear and the step-up gearing.
 8. The converter of claim 7 wherein a pin and slot rotary driving connection is established between the rotary input and the converter shaft while permitting axial shifting of the converter shaft between its operating positions, and wherein releasable locking means is provided on the rotary input engageable with the pin of the pin and slot driving connection for maintaining the converter shaft in a selected first and second operating position.
 9. The converter of claim 7 wherein the step-up gearing includes a second converter drive gear mounted on the converter shaft and a third compound gear in meshing engagement therewith, said first converter drive gear upon being coupled to the converter shaft by the detent establishing said second operating position with a stepped-up drive ratio of 1:4 from the rotary input to the rotary output via the step-up gearing for volume registration and cost computation for quarts of fuel dispensed, said second converter drive gear having a detent receiving aperture which upon axial shifting of the converter shaft with its detent received in the aperture of said second converter drive gear establishes a third operating position with a 1:3.785 drive ratio from the rotary input to the rotary output via the step-up gearing for volume registration and cost computation for liters of fuel dispensed.
 10. The converter of claim 9 wherein the rotary input has a tubular end for telescopically receiving the counter shaft, the rotary input having an axially extending slot, wherein the converter shaft has a diametrically extending pin with an end of the pin received in the slot of the rotary input and providing a pin and slot rotary driving connection between the rotary input and the converter shaft, wherein first and second annuli are formed in the rotary input between the ends of its slot therein, and wherein a pair of locking rings are releasably secured in the annuli of the rotary input and which locking rings are engageable with the end of the pin for selectively retaining the converter shaft in first, second and third operating positions. 